Previous research is surprisingly uninformative about why the majority of adolescents with mental health problems fail to receive mental health services, even when adults recognize they have a problem and could provide a "gateway" to care. Initial studies by Dr. Stiffman reveal that gateway providers are unable to help the youths, and frustrated with their level of knowledge, and the structural constraints (organization, management, financing) in which they must operate. To understand the pathway to mental health services, we are building upon the currently funded Youth Services Project (YSP) (R24 MH50857). We explore a model of mental health services use which includes the moderating effect of gateway providers' perceptions and structural, organizational factors on the relationship between adolescents' use of mental health services and need, predisposing characteristics, and enabling characteristics (availability, accessibility, acceptability, and affordability). We examine this service model with four separate but linked sets of data: 1) Secondary data from the Youth Services Project which contains: a) 796 youths' reports of predisposing and need characteristics, service use, and pathways to care, and b) census data concerning youths' neighborhoods; 2) Primary data from interviews with the youths' "gateway" providers concerning: a) providers; assessments of the youths' predisposing and need characteristics, and b) providers; perceptions of enabling characteristics and the structure of the service system; 3) Primary data from case record reviews; and 4) Primary data from public records concerning the structure, organization and financing of providers' "gateway" sectors. This study provides the first opportunity to test an extensive model of pathways to service use from both provider and client perspectives. We will characterize 1) differences in the perception of need and knowledge of services between gateway providers who link mentally ill youth to mental health services and those who do not; 2) differences in the availability, accessibility, affordability, acceptability, and to the structural characteristics of mental health services that explain providers' actions in linking youths to mental health services; and 3) differences in the organizational structure (support, flexibility, resources) of gateway providers that explain providers; actions in linking youths to services.